What are the symptoms and treatment of hypothyroidism?

Symptoms of Hypothyroidism

The common symptoms of hypothyroidism include fatigue, weight gain, cold intolerance, constipation, hair loss, dry skin, voice changes, mental slowness, muscle cramps, and menstrual irregularities. 1

Clinical Presentation

Common Physical Symptoms

• Fatigue and lethargy (68-83% of patients) 2
• Weight gain (24-59% of patients) 2
• Cold intolerance 1
• Constipation 1
• Dry skin and hair loss 1
• Voice changes (hoarseness) 3
• Muscle cramps and myalgias 3
• Edema 3

Cognitive and Neurological Symptoms

• Mental slowness and intellectual impairment 1
• Memory loss and difficulty concentrating (45-48% of patients) 2
• Depression 3
• Irritability 1

Reproductive Symptoms

• Menstrual irregularities (approximately 23% of patients) 2
• Oligomenorrhea or menorrhagia 2
• Infertility and increased risk of miscarriage 2

Cardiovascular Symptoms

• Bradycardia 3
• Hyperlipidemia 3
• Increased risk for cardiovascular events, including heart failure 2

Diagnostic Evaluation

Laboratory Testing

• TSH testing is the recommended initial screening test 1
• Elevated TSH with low free T4 confirms overt hypothyroidism 1
• Additional testing for thyroid antibodies (TPO) may be warranted to identify autoimmune causes 1

Special Considerations

• Symptoms may be subtle and nonspecific, especially early in the disease 4
• Subclinical hypothyroidism is defined as elevated TSH with normal T4 levels 1
• Thyroid function should be assessed annually in patients with known risk factors 1

Treatment

First-Line Therapy

• Synthetic levothyroxine is the standard treatment 5, 2
• Initial dosing is typically 1.5-1.8 mcg/kg/day for most adults 4
• Lower starting doses (12.5-50 mcg/day) should be used for patients over 60 years or with heart disease 4

Monitoring and Dose Adjustment

• TSH monitoring should be performed 6-8 weeks after initiating treatment 2
• Once stabilized, annual monitoring is recommended 2
• Goal is to normalize TSH levels (typically 0.4-4.0 mIU/L) 6

Special Populations

• Pregnant women with hypothyroidism should increase their weekly dosage by 30% 4
• Elderly patients require more careful dosing to avoid cardiovascular complications 5

Complications of Untreated Hypothyroidism

Short-Term Complications

• Worsening symptoms affecting quality of life 1
• Insulin resistance and hyperglycemia in patients with diabetes 2

Long-Term Complications

• Cardiovascular disease and increased mortality 6
• Reproductive health issues including disrupted ovulation and infertility 2
• Progression to myxedema coma (severe hypothyroidism with decompensation) 2
  • Characterized by hypothermia, hypotension, and altered mental status
  • Requires intensive care treatment
  • Has a mortality rate of up to 30%

Common Pitfalls in Diagnosis and Management

• Misattribution of nonspecific symptoms to other conditions 4
• Inadequate treatment leading to persistent symptoms 6
• Overtreatment causing iatrogenic hyperthyroidism 1
• Failure to adjust dosage during pregnancy or with aging 5
• Not considering drug interactions that may affect levothyroxine absorption 6

Remember that hypothyroidism is often a lifelong condition requiring continuous treatment and monitoring to maintain optimal thyroid hormone levels and prevent complications 6, 7.